Please use this identifier to cite or link to this item: https://doi.org/10.21256/zhaw-3382
Publication type: Article in scientific journal
Type of review: Peer review (publication)
Title: Petrophysical properties of opalinus clay drill cores determined from Med-XCT images
Authors: Keller, Lukas M.
Giger, Silvio B.
DOI: 10.21256/zhaw-3382
10.1007/s10706-019-00815-2
Published in: Geotechnical and Geological Engineering
Volume(Issue): 37
Issue: 4
Page(s): 3507
Pages to: 3522
Issue Date: 2019
Publisher / Ed. Institution: Springer
ISSN: 0960-3182
1573-1529
Language: English
Subjects: Medical X-ray tomography; Shale density; Shale composition; Opalinus Clay
Subject (DDC): 551: Geology and hydrology
Abstract: The determination of petrophysical properties such as density, porosity and mineralogical composition of the rock are key objectives in cored sections of drilling campaigns. In view of the large amount of sample material that accumulates during a drilling campaign, a seamless determination of the properties along the cores is not feasible if only direct methods are used. Therefore, fast, non-destructive and affordable methods have been developed. Three-dimensional images of Opalinus Clay drill cores were acquired by using a medical X-ray computed tomographic scanner (med-XCT). The CT numbers of the images were density calibrated, which allowed to determine bulk density variations along drill cores. Then, a relationship between rock composition and bulk density was built in form of linear regression models to predict the porosity or the contents of major components from density calibrated image data. This relationship was established on the basis of rock samples, of which mineralogical compositions and porosities were measured in the laboratory. It turned out that the bulk density of Opalinus Clay is systematically related to porosity and the contents of clay minerals, quartz and calcite. With increasing density, porosity and clay minerals content decrease. This is because the pores and clay minerals together form the porous clay matrix and are thus structurally connected. The density of the porous clay matrix is comparatively low, and its content therefore controls the bulk density of Opalinus Clay. With a decrease in the content of the porous clay matrix, the calcite and quartz contents both increase, which is associated with an increase in bulk density. No systematic behavior was found for the accessories. Thus, their influence on bulk density is considered to be small. Med-XCT in combination with reference samples allows the determination of the rock composition and porosity along drill cores. In the case of Opalinus Clay, a larger number of reference samples (>~50) are required to predict the properties with confidence.
Further description: Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)
URI: https://digitalcollection.zhaw.ch/handle/11475/15260
Fulltext version: Published version
License (according to publishing contract): Licence according to publishing contract
Restricted until: 2024-01-01
Departement: School of Engineering
Organisational Unit: Institute of Computational Physics (ICP)
Appears in collections:Publikationen School of Engineering

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Keller, L. M., & Giger, S. B. (2019). Petrophysical properties of opalinus clay drill cores determined from Med-XCT images. Geotechnical and Geological Engineering, 37(4), 3507–3522. https://doi.org/10.21256/zhaw-3382
Keller, L.M. and Giger, S.B. (2019) ‘Petrophysical properties of opalinus clay drill cores determined from Med-XCT images’, Geotechnical and Geological Engineering, 37(4), pp. 3507–3522. Available at: https://doi.org/10.21256/zhaw-3382.
L. M. Keller and S. B. Giger, “Petrophysical properties of opalinus clay drill cores determined from Med-XCT images,” Geotechnical and Geological Engineering, vol. 37, no. 4, pp. 3507–3522, 2019, doi: 10.21256/zhaw-3382.
KELLER, Lukas M. und Silvio B. GIGER, 2019. Petrophysical properties of opalinus clay drill cores determined from Med-XCT images. Geotechnical and Geological Engineering. 2019. Bd. 37, Nr. 4, S. 3507–3522. DOI 10.21256/zhaw-3382
Keller, Lukas M., and Silvio B. Giger. 2019. “Petrophysical Properties of Opalinus Clay Drill Cores Determined from Med-XCT Images.” Geotechnical and Geological Engineering 37 (4): 3507–22. https://doi.org/10.21256/zhaw-3382.
Keller, Lukas M., and Silvio B. Giger. “Petrophysical Properties of Opalinus Clay Drill Cores Determined from Med-XCT Images.” Geotechnical and Geological Engineering, vol. 37, no. 4, 2019, pp. 3507–22, https://doi.org/10.21256/zhaw-3382.


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